On the old Internet (Web 1.0) communication was in one direction only i.e. from author to reader. On the new Internet (Web 2.0) communication is not only two way but is a community affair with everybody involved with comments on comments and entire conversations.
WordPress blogs allows reader comments and discussion but there are a number of settings that you can implement to control how comments work. Log into your dashboard and check out ‘Settings, Discussion’. Here you will find many different settings that can make comments work for you.